For a new lawn, prepare a level, firm seedbed with a fine, crumbly surface so grass seed can make contact with the soil. For a bare patch or an existing lawn, you can prepare a much smaller area and leave healthy grass in place.
Work when the soil is neither frozen nor waterlogged. Spring and early autumn are useful sowing windows, provided the soil is workable and you can keep the surface moist as the seedlings emerge. See our guide to when to sow grass seed for choosing the right conditions.
Preparing bare ground for a new lawn
Start several weeks before sowing if possible. Remove rubbish, large stones and unwanted vegetation. Dig out the roots of perennial weeds such as bindweed and couch grass; new shoots are easier to deal with before the lawn is sown.
If the ground is hard and compacted, loosen it with a fork or by digging. The RHS suggests digging compacted soil to about 20cm for a new lawn. Avoid digging when the soil is saturated, as working it wet can damage its structure. On very free-draining soil, well-rotted compost incorporated into the ground can help it retain moisture.
Level obvious high spots and hollows, then let disturbed soil settle. The RHS guide to sowing a new lawn recommends leaving dug soil to settle for several days or, ideally, longer. Remove any weed seedlings that appear before sowing.
Firm and rake the surface
Walk over the ground in small, shuffling steps, crossing it in different directions to firm loose areas. Rake in several directions, breaking up clods and removing large stones. Fill any hollows that become apparent, firm those areas and rake again.
Aim for an even surface with small crumbs of soil at the top. It should feel firm underfoot, without deep footprints or loose pockets that will settle into dips later.
Preparing a bare patch
Remove loose dead grass and debris, then lightly fork or rake the exposed soil. If the patch is hollow, add suitable topsoil or incorporate garden compost before gently firming and levelling it with the surrounding lawn. There is no need to dig up healthy grass around a small patch.
Consider why the patch appeared. A route used every day may need a stepping stone or a change in traffic; a persistently wet area needs its drainage investigated. A shade-tolerant mix can help where light is limited, although grass still needs some light. Our patch repair guide covers the next steps.
Preparing an existing lawn for overseeding
Mow the lawn and clear loose clippings and debris. Rake enough to open the surface between existing plants, allowing the seed to reach soil. Where there is substantial dead material or compaction, more preparation may be needed, but avoid stripping out healthy grass unnecessarily. Follow the overseeding guide for the full sequence.
Ready to sow
Measure the area and use the seed packet’s recommended rate for a new lawn, patch repair or overseeding, as applicable. Our guide to how much grass seed to use shows how to calculate the area and quantity.
Distribute seed evenly and follow the packet’s directions for covering or lightly raking it in. Water gently so the seed is not washed into piles, and keep people and pets off the newly seeded area while it establishes. The new seed watering guide explains how to judge when the surface needs water.